Probably because building targets with tools outside of the workspace is an antipattern, as it violates hermiticity principles. In fact, Bazel generally makes it quite hard to do this, so anyone who ends up in this scenario must have jumped through many hoops to get there.
I agree that the linked issue is legitimate, but I'd argue that this isn't a problem Bazel itself needs to solve--you should fix your build to be fully hermetic.
I agree that the linked issue is legitimate, but I'd argue that this isn't a problem Bazel itself needs to solve--you should fix your build to be fully hermetic.